This invention relates to containers which can be opened and closed while continuing to achieve a seal between the cap and the container and also allowing for gas flow into and/or out of the container.
A good seal is especially desirable if the substance in the container needs protection from the outside environment, such as a powdered beverage mix which can cake with continuous exposure to very humid air. It is desirable to be able to manufacture an inexpensive cap and container assembly, which can be used for initial packaging of the product prior to sale, and which can continue to be opened and resealed by the purchaser of the product.
It is also desirable to allow for gas to flow into and/or out of the container, while still maintaining a sufficient seal, to reduce or prevent denting or bursting of the container, which can be caused when a sealed container assembly is moved from a high altitude to a low altitude or moved from a low altitude to a high altitude.
Some existing containers are too expensive for the packaging of inexpensive products, difficult to reseal effectively, or simply cannot be resealed effectively. Existing containers often do not permit gas to flow into and/or out of the container, likely causing the undesirable denting described above.
The invention pertains to a method and apparatus allowing for gas flow into and/or out of a container assembly. The container assembly comprises a container having a sealing surface, and a cap having a sealing surface. The sealing surfaces of the container or the cap or both given a texture that is polished or made coarser, as desired In this way the sealing surface of the container and the cap cooperate with one another to form a seal and to allow gas to flow into or out of the container assembly.
In one embodiment, the container includes a base and a neck and the cap includes a protrusion. In such an embodiment, at least a portion of the neck is the sealing surface of the container, and at least a portion of the protrusion is the sealing surface of the cap.
The sealing surfaces cooperate with one another, and temporarily deform a shape of the cap, the neck and/or both. The cooperation also forms a seal between the cap and the container, and in one embodiment, an extent of the deformation can be limited by contact between stopping surfaces, blocking tighter engagement of the cap with the container.